Any Disadvantage Using DVI-HDMI Adapters?

I don't think so - quality is not compromised - after all it is all digital. Provided the source is outputting data that the TV can decode. I use DVI-D (digital) to HDMI from my Mac to my HD TV - this way I can select tracks to play from the listening position by using a wireless keyboard. Note that when (if) they start protecting video against piracy then some devices will not accept digital HD signals except through HDMI...

( I had to hack the Mac standard operating system by programming the Video card to output 720p, as this was not a native resolution on Mac OS but it all works seamlessly now)

What kind of DVI does you rprojector support????

There are TWO kinds.....analog and digital!!!

Some devices accept both and will default to digital if it detects the signal.

If you have an analog DVI only then it is probably not much different than component - although component cables may have better shielding...